From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> The function update_mmu_cache could be called by user-io mapping. There is no space of struct page in mem_map for the pte. Just ignore the user-io mmaping in update_mmu_cache. Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> --- arch/csky/abiv2/cacheflush.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/csky/abiv2/cacheflush.c b/arch/csky/abiv2/cacheflush.c index 790f1ebfba44..39c51399dd81 100644 --- a/arch/csky/abiv2/cacheflush.c +++ b/arch/csky/abiv2/cacheflush.c @@ -12,6 +12,9 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, unsigned long addr; struct page *page; + if (!pfn_valid(pte_pfn(*pte))) + return; + page = pfn_to_page(pte_pfn(*pte)); if (page == ZERO_PAGE(0)) return; -- 2.17.1